Sofa



FIG. 1 is a top, front and side perspective view of a sofa showing our new design;

FIG. 2 is a side elevational view thereof from the left of FIG. 1;

FIG. 3 is a side and top perspective view thereof from the side opposite that shown in FIG. 3; and,

FIG. 4 is a rear elevational view thereof. 

The ornamental design for a sofa, as shown and described. 